files/en-us/web/api/rtcrtpreceiver/getcontributingsources/index.md
{{APIRef("WebRTC API")}}
The getContributingSources() method of the {{domxref("RTCRtpReceiver")}} interface returns an array of objects, each corresponding to one CSRC (contributing source) identifier received by the current RTCRtpReceiver in the last ten seconds.
getContributingSources()
None.
An array of objects, each describing one of the contributing sources that provided data to the incoming stream in the past ten seconds. These objects contain the following properties:
audioLevel {{optional_inline}}
: A floating-point value between 0.0 and 1.0 specifying the audio level contained in the last RTP packet played from the contributing source.
The value is on a linear scale and is defined in units of dBov, or decibels (overload). This is the amplitude relative to the point at which clipping of the audio begins to occur. A value of 1.0 represents 0 dBov (maximum volume), a value of 0.0 represents silence, and a value of 0.5 represents approximately 6 dB SPL (decibels of sound pressure level) change in the sound pressure level from 0 dBov.
If this property is not present then no volume level was provided by the source.
rtpTimestamp {{optional_inline}}
timestamp, was initially sampled or generated.
It may be useful for sequencing and synchronization purposes.source {{optional_inline}}
timestamp {{optional_inline}}
{{Specifications}}
{{Compat}}